Shoe sewing machine



Feb. 15, 1944. o. R. HMS 2,341,714

SHOE SEWING MACHINE Filed April 8 1942 Patented Feb. 15, 1944 UNITED STATES PATENT OFFIC SHOE SEWINGpMACHINE Otto R. Haas, North BeverlypMassl, assignor to United Shoe Machinery Corporation,

Flemington, N. J., a corporation of New Jersey Application April 8, 1942, Serial No. 438,143

4 Claims.

thread between the needle and the work sufficient in amount to enable the threaded needle to pass through the work without causing the thread to slide in the hook of the needle while at the same time forming uniformly tight stitches. These machines are so constructed that in order to remove or replace a faulty or broken thread arm, it is necessary to dismantle many of the operating and supporting parts of the machine or to loosen the connections to such an extent as to throw the entire machine out of adjustment before the thread finger can be removed or replaced. Reassembling and adjusting frequently thereafter are time consuming tasks.

In the machine of the Haas application, the difficulty is particularly troublesome because the operating parts of the machine are entirely enclosed within a dust excluding ornamental casing, the main supporting frame structure of which extends in front of or obscure many of the machine parts, The mountings for the frame structure therefore must be taken off to remove or replace a faulty thread arm, thus adding substantially to the difiiculties of the procedure.

The objects of the present invention are to simplify and improve the construction of a curved needle lockstitch shoe sewing machine having a thread measuring arm or hook in such a way as to simplify the operation of removing the thread arm and to render possible a replacement of the thread arm without dismantling, loosening or disassembling any of the operating or supporting parts of the machine other than the thread arm. Further objects of the invention are to provide a novel and improved thread arm construction in which the position of the arm may readily be changed and adjustments made in the amount of thread measured between the hook of the needle and the work before the threaded needle is drawn through the work and in which there is less likelihood of breakage or injury to the thread arm than in prior shoe sewing machines of the type referred to.

-att he socket the thread arm A special difliculty met in removing or replacing the thread arm of prior machines of this type is due to the construction of the entire machine and to the arrangement ofthe arm which consists of a straight slide having a hooked thread engaging forward end and a laterally projecting roll at the rearward end engaging a slot in one side of a rotary actuating cam. In order to remove or replace the thread arm, the roll must be disengaged from the actuating cam and due to the close location of other cams and operating parts of the machine, it is impossible either to remove the roll from the slide or to disengage the roll from the cam without an amount of general machine disassembly all out of proportion to the effort required in actual replacement of the thread arm itself. The machine construction which renders thread arm replacement difficult is in a stationary grooved frame member which forms a guideway for the thread arm slide and a support for a needle segment stud at the same side of the frame member with the guideway. The whole machine is so designed that the parts are compactly arranged about the point of sewing operations and the cams are so spaced along the main sewing shaft that accessibility to the cam rolls is accomplished only with long slender tools.

' Accordingly, the principal feature of the present invention contemplates the provision in a curved hook needle shoe sewing machine having a stationary grooved frame member from the grooved side of which a needle segment supporting stud projects and a thread arm in the form of a slide in the groove of the frame member with a hook at its outer thread engaging end only exposed for providing slack thread between the needle and the work, of an actuating bar slidably mounted in the groove of the frame member separate from the thread arm, provided with a socket between the ends of the groove for receiving the inner end of the thread arm to enable the hooked portion to be disconnected and replaced readily in case of injury or breakage. By providing an actuating bar separate from the thread arm, it is possible to remove the arm without disturbing the actuating barythe cam roll supported thereon or the cam so that .a major difficulty in removal or replacement of the thread arm is obviated. Also, the position of the socket between the ends of the groove eliminate any tendency for the parts to bend slide and actuating bar being kept in alignment by their support in the groove. 1

In the machine to which the invention has been applied, the needle supporting segment oscillates close to one side of the thread arm slide, the other side being enclosed by the groove of the frame member. In the preferred form of the invention, the frame member is perforated and the thread arm receiving socket is equipped with a clamp member accessible from the side of the frame member opposite the groove and needle segment, through the perforation in the frame member. A common type of wrench may be employed to loosen or tighten the clamp so that the hooked end of th thread arm may be replaced or adjusted easily to suit the conditions under which the machine is operating. As illustrated, the inner end of the thread armhas the shape of a dowel projecting lengthwise to fit within the socket on the bar, the clamp consisting of a nut movable into alignment with one of the perforations in the frame member in one position of each sewing cycle whenever replacement or adjustment of the thread arm is found desirable.

These and other features, together with the constructions, combinations and arrangements of parts hereinafter described and claimed, will be readily understood from the following description taken in connection with the accompanying drawing, in which Fig. '1 is a view in side elevation of certain operating parts including the thread arm or finger of a lockstitch shoe sewing machine embodying the features of the present invention, some of the illustrated parts having been broken away and shown in section; Fig 2 is a sectional detail view on an enlarged scale taken along the line 22 of Fig. 1; and Fig. 3 is a separated perspective View of the novel portions of the construction embodied in the thread arm, the supporting bar for the arm having been broken out and reduced in length to conserve space. i

The illustrated machine is of the same general construction and mode of operation as disclosed in the French and Meyer patent and in'the application of the present inventor above identified. The stitch forming devices of the machine comprise a curved hook needle 2, a curved awl B, a needle looper 6, a thread arm or finger 8, a rotary shuttle having a thread case Iii in which the supply of locking thread. is contained, the work operated upon being supported by a work support l2 during sewing operations. The needle and awl are mounted in segments l4 and Hi, respectively, the needle segment being arranged to oscillate on a stud is secured in a portion of the main frame of the machine. The portion of the main frame in which the needle st-ud is secured comprises a grooved bracket member 20, the groove of which forms a guideway for a slide portion of the thread arm 8. The forward end of the thread arm is hooked in order to hold securely the thread carried by the looper when the looper moves into line with the thread arm before the needle is looped and the hooked end portion is the only part of the thread arm exposed at the front of the machine. As soon as the needle is looped, the thread arm moves forward slightly and as the threaded needle hook begins to rise through the work, a bight of thread supported by the thread arm is disengaged, providing a sufficient amount to prevent the thread from being drawn taut between the needle and the work and sliding in the needle hook as it passes through the work. To actuate the thread arm of prior constructions, the inner end of the slide portion of the arm has rotatably mounted thereon a roll corresponding to the roll 22 engaged between two surfaces forming the edges of a continuous slot 24 in one side face of a cam 26.

Due to the close proximity of the working parts and of the stitch forming devices in machines of this type, there is an opportunity for the stitch forming devices to contact each other when improperly adjusted or from other causes, oftentimes with undesirable results. Continued contact of the stitch forming devices either will cause the devices to fail to operate properly or to become injured by breakage in such a way as to require ultimate removal and replacement. If the thread arm is so injured or broken, a difllcult problem arises in its replacement by reason of the compact construction of the parts and actuating mechanisms, particularly at or adjacent to the point of sewing operations. The groove of the bracket or frame member 20 in which the thread arm slide is guided is partly open at the side of the bracket member past which the needle supporting segment M oscillates, access being prevented, as illustrated in Fig. 2, adjacent the point of sewing operations, by the needle segment. In order to remove the thread arm from the prior machine, it is necessary to disengage the roll at the inner end of the arm from the slot 24 of the cam 26, since the roll is mounted directly on the thread arm. The roll 22 itself, so far as possibility of removal from the thread arm is concerned, is extremely inaccessible due to the presence of other cams and actuated mechanisms in close proximity thereto. A common method of removing the thread arm from the patented machine is by disconnecting'the supporting bearings for the main sewing shaft or by loosening them sufficiently to enable the Whole shaft to be moved in a direction to disengage the sides of the slot 24 from the roll 22. Thereafter, by careful manipulation and complicated movements, the thread arm may be withdrawn and disengaged from the groove in the bracket member 2a and replaced with a new thread arm by similar movements performed in the reverse order. Necessarily such operations require the most expert trained ability and excessive consumption of time.

In order to remove a faulty thread engaging portion of the thread arm 8 from the machine embodying the features of the present invention, the thread arm slide is actuated by a bar 28 separate from the arm and slidably mounted Within the groove of the frame member 20 in alignment with the thread arm slide. The bar 23 carries at its inner end the stud for the cam roll 22 which may remain in engagement with the slot 24 of the cam 26 when the thread arm slide is removed. To connect the thread arm to the bar, the bar is provided with a socket within and between the inner and outer ends of the groove in the frame member 28 and a recess 29 is formed in the frame member in proper position to clear the socket on the bar. The inner end of the thread arm is reduced tot'ne shape of a dowel indicated at 30, projecting lengthwise of the thread arm slide to fit within semi-cylindrical gripping surfaces 32 and 34 of the socket which are provided one on the bar 28 and one on a clamp plate 36 having a threaded stud 38 projecting at right angles thereto and passing through the bar 28. To secure a compact construction and one which will prevent relative movement of the clamp plate lengthwise of the bar 28, the plate has a squared projection 40 from which the threaded stud 33 projectsto fit within a flat sided recess 42 in the bar 28.

tions met during sewing operations.

The squared projection has a passage to receive the dowel 30 beneath the stud 38, th arrangement being such that when the plate is clamped to the bar 28, the frictional engagement between the dowel 3B and the surfaces of the bar and plate will prevent removal of the hooked end of the thread arm. For clamping the socket members together, the projecting end of the stud receives a nut 44 acting against the outer surface of the bar 28 when rotated in a clamping direction.

Due to the presence of the needle segment It and an actuating segment 45 engaging the needle segment, the exposed side of the thread arm and bar in the groove must be free from substantial lateral projections so that the only practical location for the projecting portions of the socket including the clamp nut 44 is within a recess of the frame member 20. To permit easy access to the clamp nut, the frame member is perforated at 46 with a sufficiently large opening to receive a common form of wrench for the nut M, the

wrench being inserted through the opening (it from the side of the frame member opposite to that having the groove and the projecting needle segment receiving end of the needle stud it, which extends from the same side of the frame member. The location of the clamp nut in the position indicated is the only possible arrangement, since other operating parts obscure easy access to other portions of the thread arm slide. If located elsewhere, a clamp nut exposing perforation would so weaken the parts of the guideway or frame member which form the groove as to render such arrangement impracticable or subject to other difficulties. Also, the dowel 30 is reinforced against bending by the support offered to the parts at either side of the socket in the guideway. The nut 44 moves with the actuating bar 28 during sewing operations from alignment with the opening 46 inwardly of the machine, but the position of the stud and clamp nut are so selected on the bar as to render the nut easily accessible when the thread arm isin its forward position. One advantage of this construction for the particular socket on the bar is that the position of the thread arm may be changed lengthwise on the actuating bar 28 to enable the thread arm to act more effectively according to condi- Loosening the clamp nut and changing the position of the dowel 30 in the socket is a simple operation, and even in case of accidental contact between the stitch forming devices during sewing, the frictional engagement between the dowel and the socket ordinarily will be insufficient to cause breakage or injury in the hooked end of the thread arm, the dowel sliding in the socket before this occurs.

The invention having been thus described, what is claimed is:

1. In a shoe sewing machine having a curved hook needle, a stud about which the needle oscillates, a stationary grooved frame member from the grooved side of which the needle supporting portion of the stud projects, the combination with a thread arm in the form of a slide in the groove of the frame member with a hook portion only at its outer thread engaging end exposed outside the frame member for providing slack thread between the needle and the work sufficient in length to prevent the thread from sliding through the hook of the threaded needle while being withdrawn from the work, and an actuating slidably mounted bar within the groove of the frame 'member in alignment with the thread arm slide provided with a releasable socket between the ends of the groove for receiving the inner end of the thread arm slide to enable the thread arm to be replaced readily in case of injury or breakage.

2. In a shoe sewing machine having a curved hook needle, a stud about which the needle oscillates, a stationary grooved and perforated frame member from the grooved side of which the needle supporting portion of the stud projects, the combination with a thread arm in the form of a slide in the groove of the frame member with a hook at its outer thread engaging end for providing slack thread between the needle and the work sufiicient in length to prevent the thread from sliding through the hook of the threaded needle while being withdrawn from the work, an actuating bar within the groove of the frame member in alignment with the thread arm slide provided with a socket for receiving the inner end of the thread arm slide, and a releasable clamp for the socket accessible through a perforation in the frame member to enable the thread arm to be replaced readily in case of injury or breakage of the hooked end of the thread arm.

3. In a shoe sewing machine having a curved hook needle, a stud about which the needle oscillates, a stationary grooved frame member from the grooved side of which the needle supporting portion of the stud projects, the combination with a thread arm in the form of a slide in the groove of the frame member with a hook at its outer thread engaging end for providing slack thread between the needle and the work sufficient in length to prevent the thread from sliding through the hook of the threaded needle while being withdrawn from the work, a dowel projecting lengthwise of the thread arm slide at the inner end of the slide, an actuating bar within the groove of the frame member in alignment with the thread arm slide, a socket for receiving the dowel on the actuating bar, and a nut for clamping the dowel in the socket accessible for rotation through a perforation in the frame member to enable the dowel to be released or clamped readily without disturbing the position of the needle on its supporting stud.

4. In a shoe sewing machine having a curved hook needle, a stud about which the needle oscillates, a stationary grooved frame member from the grooved 'side'of which the needle supporting portion of the stud projects, the combinationwith a thread arm in the form of a slide in the groove of the frame member with a hook at its outer thread engaging end for providing slack thread between the needle and the work sufficient in length to prevent the thread from sliding through the hook of the threaded needle while being withdrawn from the work, and an actuating bar within the groove of the frame member in alignment with the thread arm slide provided with a thread arm receiving socket comprising a semi-cylindrical surface on the bar, a plate having a cooperating semi-cylindrical surface, a projection on the plate provided with a clearance passage for the thread arm and arranged to fit a recess in the bar, a clamping stud on the projection of the plate arranged to pass through the bar, and a nut on the stud for clamping the plate and bar together.

OTTO R. HAAS. 

